1. Field of the Invention
The invention is directed to the field of tie means for disposition about one or more articles.
2. Description of the Prior Art
Bundling straps and the like for bundling together articles such as wire harnesses and the like are well known in the art and generally comprise an elongated plastic element of suitable flexibility having, at one end, an apertured head portion containing a locking barb or tongue for engagement with the body portion of the device as the body portion is drawn through the aperture in the head portion to form a loop about one or more articles to be enclosed therewithin. Prior art devices employing multiple barb arrangements are exemplified in U.S. Pat. No. 3,717,906 issued to Wells on Feb. 27, 1973, and in U.S. Pat. No. 3,739,429 issued to Kohke on June 19, 1973 and assigned to the assignee of the instant invention, the former patent disclosing a device in which a pair of barbs depending obliquely from opposing sidewalls of the apertured interior of the head portion of the tie are arranged to interlock with respective teeth located on opposing surfaces of the body portion of the tie. Otherwise, locking takes place in the conventional manner, i.e., by offset engagement between the barbs and the teeth wherein the barbs are subjected to a rotating torque tending to drive the free end of the barb deeper into the body portion of the strap upon attempted disengagement. The latter patent to Kohke also shows a pair of obliquely oriented barbs located in the apertured head portion of the device. However, the multiple barb arrangement shown in the Kohke patent is employed merely to provide a separate barb for each of a plurality of body portions extending from the head portion. Both types of devices, however, operate in essentially the same manner in that the barbs are pivotingly coupled within the head portion and are designed to pivot slightly about one end, wherein the force applied thereto upon attempted withdrawal of the strap body from the head portion is directed along an axis offset from the longitudinal axis of the barb, resulting in a bending moment tending to collapse or deform the barb, thus seriously limiting the usefulness and reliability of the tie where positive locking action is necessary or desirable.